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Universitat Politècnica de Catalunya. Departament de Ciència i Enginyeria Nàutiques

Document typeDoctoral thesis

Defense date2011-07-19

PublisherUniversitat Politècnica de Catalunya

Rights accessOpen Access

Abstract

The objectives of this thesis are the layout of a model for the calculation of the NOx emissions from the ships during the port operations, the development of a tool to carry out the mentioned calculation, the validation of the method applied and also the validation of the software designed jointly by the General Directorate of the Merchant Marine (this researcher has represented
this organization) and the University of Vigo.
So, bearing in mind the above paragraph, it is firstly applied an analytic method to calculate the NOx from the marine diesel engines. This methodology is applied to the calculation of the emissions generated in a model port by a specific type of ship.
In this stage all the containerships that called at Barcelona in 2009 have been selected.
The methodology distinguishes and analyses in depth the different operative stages that take place during the port period and it has initially been completely developed in two containerships with the aim of enlightening the method, afterwards the
calculation has been extended to the rest of the ships indicated in the above paragraph by means of a worksheet that incorporates all the details applied in the two model ships.
Later on a calculation as weighted emissions is carried out in the same model ships above indicated according with the test
cycles defined in the NOx Technical Code. This stage of the thesis can be justified due to the fact that for validating the
analytic method used in the paper, it is necessary a normalized base to compare the results, so the results obtained as total
weighted emissions by using the test cycles of the mentioned regulation have been required and used.
This calculation is firstly developed by the method defined in the thesis and secondly by means of the simulation software
indicated in the first paragraph.
After getting the weighted emissions results, queries and searches have taken place to obtain the values declared by the
engines makers of the model ships. These values are included in the thesis body and a comparative analysis of the different
results is made in the conclusions section.
The analytic method referred to at the beginning of this summary is supported by the use of different variables. Firstly the
called emission factors (EF) have to be fixed. They are defined for the different types of engines and for each pollutant.
The EF¿s mainly depend on different parameters that are detailed in the thesis. The acquisition of the EF¿s is done
empirically, mainly by the engines makers and the Recognized Organizations responsible for the pre-certification survey.
In this case, reference values for different engines classified by type and nominal speed were obtained through the professor
James J. Corbett from the University of Delaware. In the thesis, they have been extrapolated and approximated to polynomial
functions to cover the engine working range required in this paper. Later on, bearing in mind the typology of propulsion and
generating plants of the ships studied, these plants have been classified in the different curves previously designed to get the
most accurate results.
The specific fuel oil consumption (SFOC) is other main variable of the method developed in the thesis. To estimate the
SFOC¿s of the ships engines, a division based in reference engines has been carried out and after that the ships engines
have been classified in its corresponding division.
The reference engines SFOC¿s have been supplied by the manufacturers themselves, which only provide the values
corresponding to the common working loads. Afterwards, they have been extrapolated and approximated to polynomial
functions for the complete range required by the operative conditions at port.
Once the emission factors and the specific fuel oil consumptions are known and after estimating the load ranges of the main
and generating plants and the timing taken by each operative phase, the NOx emissions for all the containerships of the thesis are obtained.

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